The objective of this study is to investigate various pathological and metabolic properties of the encephalitogenic myelin basic protein which apparently are revealed by changes in the conformation of the protein and its peptides. This includes not only determining whether conformational changes in EAE-inducing peptides can explain clinical differences in this disease, but also includes defining the difference in cell mediated (CM) response by HEAE and EAE, determining which non-encephalitogenic regions will give positive CM responses, determining the involvement of the myelin BP in peripheral nerve disease, and defining the active unit within the protein responsible for the fibroblasts growth activity. We have found that cell-mediated response in EAE corresponds to the EAE-inducing ability of the tested myelin basic protein (MBP) peptides. Furthermore, we have located the fibroblast growth factor (FGF) site within MBP and have discovered a similar region within pituitary FGF. Finally, we have localized the neurogenic determinant of MBP.